Integrated circuits (ICs) are used in a wide range electronic devices produced by a large number of system manufacturers. ICs are seldom manufactured (fabricated) by the system manufacturer, or the electronic device designer. Instead, ICs are manufactured by an IC foundry to the specifications of the electronic device designer and assembled by the system manufacturer.
Prior to the development of base platforms, described below, IC foundries supplied design tools to device designers to enable device designers to design ICs that incorporated circuit designs unique to the device designer. The design tools were tailored to the IC foundry's technology to enable the device designer to complete an IC design without knowledge of the details of the fabrication technology.
More recently, IC foundries developed base platforms that are configurable to meet the device designer's requirements. The base platform contained layers of semiconductor, such as silicon layers, with hardmacs and a transistor fabric diffused into the semiconductor, but without metal interconnection layers. The hardmacs were composed of embedded transistors and other electronic elements diffused into the semiconductor to form standard circuit elements, such as memories, transceivers, processors, converters, input/output (I/O) modules, etc. The transistor fabric comprised an array of pre-diffused transistors arranged in a grid pattern and configurable to custom logic and memory. An example of a transistor fabric is described in U.S. Pat. No. 6,823,499 for “Method for Designing Application Specific Integrated Circuit Structures” by Vastisha and Delp and assigned to the same assignee as the present invention.
Some base platforms contained configurable logic blocks (CLBs) that could be configured into field-programmable gate array devices (FPGAs) by a configuration program fabric to perform specific functions for which the FPGA was designed. In some cases, regions were provided on the base platform to receive custom circuit portions. The custom logic, custom memories, custom circuit portions and configuration program fabric are called customer intellectual property, or customer IP.
Based on a functional design, and using tools supplied by the IC foundry or agent, the device designer produced one or more metallization layers for the base platform to configure the transistor logic into custom logic and memory, to create one or more configuration memories that contain firmware to configure the CLBs (if any), and to interconnect the circuit elements, thereby configuring the platform into a custom IC.
In use, the user selected a base platform containing hardmacs, transistor fabric, CLBs as appropriate and regions for custom circuit portions as appropriate. The base platform was selected so that when configured, the resulting configured platform met the user's requirements for the needed IC. Using tools supplied by the IC foundry, the user defined the metallization layer(s) to interconnect the elements and configure the transistor logic and CLBs to create custom logic and memory in the platform begin configured into a custom IC. Hence, the user created the customized logic and/or FPGA in the form of a configured platform having the metal interconnect layers and firmware (for FPGAs) to meet the device designer's requirements.
There is a wide range of types of ICs. Consequently, foundries provided families of base platforms to perform various functions, with members of the families providing specific sets and arrangements of diffused elements. The user selected a base platform and customized it to configure it into a configured platform best meeting the user's needs. As used herein, the term “base platform” refers to a platform yet to be configured into a functional IC by metallization layers, custom logic and memory in the transistor fabric, custom circuit portions in the defined regions and program fabric for CLBs (for FPGAs). The term “configured platform” refers to a functional device formed from a base platform and the included metallization layers. Examples of such configurable base platforms are the RapidChip® slices available from LSI Logic Corporation of Milpitas, Calif. RapidChip slices permit the development of complex, high-density ICs in minimal time with significantly reduced design and manufacturing risks and costs.
In practice, the selected base platform contained hardmacs that were not used in the completed design. Nevertheless, the benefits of reduced cost and time to fabricate configured platforms fabricated from base platforms offset the slightly larger size of those platforms due to unused elements.
Platform suppliers have found it necessary to maintain and support growing numbers of base platform families and family members. More particularly, the number of base platforms proliferated to meet growing user requirements, adding to the expense of the families of platforms and the tools to support them. It is, therefore, desirable to reduce the number of base platforms while extending the range of platform families. The present invention is directed to a novel base platform and to its combined use with standard die to create composable system-in-package constructions. Consequently fewer base platforms are required for each family of platforms, resulting in lower costs of creating and supporting the families of platforms.